1. Field of the Disclosure
The disclosure relates to a guide pin for aligning and mating fiber optic ferrules. In particular, the disclosure relates to a guide pin having a flexile feature for aligning and mating multi-fiber optical ferrules that have a large pin-to-bore fit.
2. Technical Field
In mating multi-fiber molded ferrules, guide pins are necessary and accepted devices to achieve a high degree of precision for axially aligning and optically coupling a plurality of optical wave guides. In the past, the quality of the optical waveguide coupling was totally dependent upon a precise friction fit between the metallic guide pin and the guide pin bore of the molded polymer ferrule. This precision was then dependent upon the degree of tolerance between the guide pin bore inner diameter and the guide pin outer diameter, which was at the mercy of temperature fluctuations and changes in relative humidity. Further, tolerance stacking of the various components in the construction of the molded optical ferrules and the metallic guide pins contributed to poor inter-mating performance between the guide pin and the molded optical ferrule, subsequently causing poor optical mating performance between optical wave guides.
Typically, metallic guide pins have a nominal diameter of 0.700 millimeters (mm) More specifically, guide pins usually have a diameter of 0.698 mm to 0.699 mm, with 0.0000 mm to 0.0005 mm cylindricity. Molded polymer multi-fiber ferrules have guide pin bore diameters of 0.6990 mm to 0.6996 mm. Being molded from a polymer, polymer ferrules have issues of parallelism and surface roughness for the guide pin bores that must be accounted for. Guide pins with the smallest diameter mated to the bores with the largest acceptable diameters can experience a so called “sloppy” fit, with unreliable optical performance due to lateral offset and torsion. Guide pins with the largest acceptable diameters mated to ferrules with the smallest acceptable diameters can experience excessively tight fits that can lead to unreliable optical performance due to gaps between polished optical waveguides and, worse, damage to the ferrule itself. Even so called perfectly mated guide pins and bores in the prior art can experience unreliable mating due to excesses in humidity, the presence of debris in the bore, and scoring on the pin shaft, all of which can affect how well the pins mate to the bores.
What is needed is a new guide pin that can adapt to tight or loose pin-to-bore fits, whether unintentional or by design, to ensure consistently reliable optical mating of optical wave guides in molded multi-fiber optical ferrules.